By Miyoung Kim SEOUL (Reuters) – Analysts fell under Samsung Electronics Co Ltd's marketing spell when they made what they now admit were hopelessly optimistic forecasts for its smartphone sales. Samsung's huge share of the high-end smartphone market also persuaded some analysts to downplay industry data pointing to a fast-saturating segment, a reality that is already eating into sales of Apple Inc's iPhone 5. Woori Investment & Securities, one of South Korea's largest securities firms, cut its outlook for Samsung's earnings and target share price on June 5. It was the first to adjust its …